Get Dynamic Lighting After the Fact with Photoshop

Adobe Photoshop is a wonderful post production tool for
photographers, and with this program you can accomplish more than just
your basic touch ups. It is possible to achieve dynamic lighting in Photoshop after your shoot, you just need to know how to make the program work for you.

Step 1: Exposure

Depending on how you wish to adjust the lighting, exposure is a good
place to start if you plan on making large adjustments. This will be
the first of your broad strokes.

At the top, select 'Image'->'Adjustments'->'Exposure.' You'll
be able to over-exposure or under-expose the image in these controls.
While you won't be able to retrieve information that might have been
lost when the image was taken due to poor exposure, you can still
adjust and off set the balances to make the overall image brighter or
darker.

Step 2: Brightness/Contrast

Once the exposure has been adjusted, you can use brightness/contrast to hone in on the settings you want.

Select 'Image'->'Adjustments'->'Brightness/ Contrast.' Adjust
the settings until you find a balance that you like. What's great about
CS4 is that you can see the adjustments in realtime without rendering
so if you don't like it, you can just hit cancel.

Step 3: Hue/ Saturation

Light affects the tone of your colors, and with hue/saturation you can help adjust the color to your liking.

Select 'Image'->'Adjustments'->'Hue/Saturation.' Tweak the settings until you find a balance that suits your needs.

Step 4: Shadow/Highlight

The final broad stroke in your lighting portrait is the
Shadow/Highlight feature which tweaks the overall brightness of the
image. This tool specifically targets areas that are darker or brighter
than the rest of the image.

Select 'Image'->'Adjustments'->'Shadow/ Highlight.' Using the
image adjustments gives you overall control over the brightness and
color of an image. They make big changes quickly and have great
influence over your photo. But, the real artistry and precision occurs
in Photoshops other functions, specifically with layering.

Step 5: Separate the Subject

The real magic of Photoshop lies in mastering the use of layers.
Layers, piled onto each other, are what creates a dynamic image. Using
the magnetic lasso tool, you are going to drag the mouse around your
subject. Take your time doing it. This steps takes time and practice.
The slightest wrong movement could cut off a chunk of the subject's
hair, making you start over again.

Once the subject is encircled by the magnetic lasso, switch to the
selection tool and slightly move the subject. You'll notice a blank
spot where they once were. You just made a new layer.

Step 6: Create Light

Make a new layer and position it between the subject and your
background. You may want to temporally turn of the view of the subject
so you can concentrate on your work. Apply a gradient overlay and a
pattern overlay on the new layer. You're going to make everything in
the new layer transparent, except for a gradient circle that will be
the color of your light.

Once you position the circle in the black spot, make adjustments so
there is some nice glow and fall off. Then make your subject visible
again and position her over the circle so that only the fall off is
visible. You may want to add a blur filter to the gradient to get the
fall off effect you want. You now have backlight.